Coal and gas furnace.



M. J. FARQUHAR. GOAL AND GAS FURNACE.

APPLICATION FILED DEO,16, 1909.

Patented Feb. 24, 1914.

3 SHEETS-SHEET 2.

INI'YJNTOR Atlorneyd'.

I. FAEQUHAR; {HAL AND GAS FURNACE.

5PPLIGATION FILED DBC.16, 1909.

1,@88,559 Patented Feb. .24, 1914.

3 SHEETS-SHEET 3- WITNESSES INVENTOR I imam $7275;

MILTON J. FARQU'HAR, 0F WILMINGTON, OHIO.

Specification of Letters Patent.

COAL AND GAS FURNACE.

Patented Feb. 24., 1914;

Application filed December 16, 1909. Serial No. 533,375.

To all whom it mag concern:

Be it known that I, MILTON J. FARQUHAR, a citizen of the United States, residing at Wilmington, in the county of Clinton and State of Ohio, have invented certain new and useful Improvements in Coal and Gas Furnaces; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to a stove or furnace having a gas burning apparatus in connection with the usual fire pit, and is designed more especially as an improvement on the type of furnace shown and described in my U. S. Patents Nos. 923,346; 923,347;

923,783 and 923,784, dated June 1, 1909.

The objects of the invention are to provide forburning gas or coal interchangeably or both together if need be; to dlstribute the flame. equally and economically to the heating surface; and to provide a simple and proportionate automatic control both to the supply of gas and to the supply of air for combustion.

The invention will be hereinafter first fully described with reference to the accompanying drawings, which form a part of this specification, and then more partlcularly pointed out in the appended claims.

In said drawings :Figure 1 is a central longitudinal section of a hot air furnace embodying my invention, the section being taken on thcline 11 of Fig. 2. Fig. 2 1s a cross-section on the line 2-2 of Fig. 1. Fig. 3 is a detail side elevation of one of the burners. Fig. 4 is a vertical cross-sectlon thereof. Fig. 5 is a horizontal section of the fire box with a plan view of the gas pipes. Fig. 6 is a detail sectional view of the gascontrolling valve. 7

The furnace illustrated in the drawings, being of the general character disclosed in my aforesaid patents, may be briefly described as follows: In the hot air casing-1 is a horizontally disposed tubular fire box or shell 2 containng a grate 3, fire linings 4 and rear bridge wall 5, providing a longitudinal fire pit or receptaclefi for coal or solid fuel, and having under the grate an air passage and ash space '7 provided by an elevated U- shaped ash pan 8, the latter having upper lateral flanges abutting against the inner sides of the shell 2. The interior arrangethem is such 'aste provide in the rear and bottom of the fire box an indirect .draft passage through which the products of combustion pass and have their final outlet at the base of the furnace front, said indirect draft passage comprising the back diving flue 9 and bottom off-draft flue 10, the latter flue belng under and straddling the sides of the ash pan. Said fire box 2 extends through the front wall of the air-casin 1 and has an exposed front plate 11 whici is provided with the various doors and dampers for controlllng the furnace. T hese include the fire door 12, the ash door 13, and a check door, damper or lid 14 of a smoke box or chamber 15 constructed on the base of said front plate and into which leads the bottom flue 10. There is also a second smoke box 16 arranged near the upper front end of the fire box or shell 2, into which there is a direct draft, controlled and normally closed by an internal damper 17 which in turn can be operated by an exterior tri-arm lever or device 18, as explained in the specification of Patent No. 923,346. Both smoke boxes 15 and 13 are in communication with the smoke pipe or stack 19. In practice the direct draft damper 17 is opened when the fire is' started and it is subsequently closed to throw the products of combustion to the indirect draft. Air to support combustion is of course admitted through the ash door and by way of the ash pan, and the ash door constitutes a valve or damper for controlling the air supply. The combustion is automatically controlled by a thermostatic governor operated by expansion and contraction of the fire box to influence or operate a pendent lever 20 which operates on the device 18 for closing the direct draft chamber 17, and on the ash door or air damper 13 and on the check door or damper 14, in the manner described in the specification .of Patent No. 923,346. As explained in said patent the lever 20 is or may be weighted on its upper end, behind its fulcrum, so that the lever will ban" outward or away from the front of the die box, and it is caused to move inward by expansion due to a rise in temperature said lever being connected just below its fulcrum to a tie-rod 21, which is connected to one end of a cross piece or member 22 placed across the back of the air casing 1 and adapted to receive the thrust of expension from the fire box through interposed thrust tran'smitt-ing means 23, the other end of said cross piece 22 being connected by another tie-rod 24 (Fig. 2) to an adjusting device (not shown) on the front" mate closing of the ash door. In operation the lever 20 responds to fluctuations in the temperature, of the firebox, thereby enlarging or restricting the'fash door opening as the temperature diminishes or increases, and in event of undue increase of temperature the inward movement of the lever will allow the ash door to close or come to a substantially closed position and at the same time lift the check door '14 and thus check the draft.

As thus far described, the furnace is substantially the same as set forth in my aforesaid Patents Nos. 923,346 and 923,784, to which reference may be made for a more detailed explanation of its construction, operation and merits; and the operation and advantages of the general construction of the fire box are more fully set forth in my Patent No. 923,347.

Referring to the gas burning attachment, a gas supply pipe 25 extends through the front wall of the fire box and inside, the latter is connected by elbow pipe sections 26 and 27 to two longitudinal gas pipes 28 and 29, which extend within and run the full length of the ash pan, one at each side, and each gas pipe supports a row of mixers and burners-30 The rear end of the gas pipes 28 and 29 are closed and may be supported in sockets formed on the rear wall of the ash pan.

One of the mixers and burners is shown in detail in Figs. 3 and 4. It comprises a hollow standard which may be composed of two parts bolted or riveted togetheras'at 31. Said standard has an enlarged or flaring base 32 which is formed to straddle the gas pipe. It 'sits upon said pipe over a port or orifice in which may be inserted a perforated plug or nipple 33 for emitting a jet of gas. Air for admixture therewith is taken under the base 32 of the standard at one or both sides of the gas pipe, as indicated by the arrows in Fig. 4. The standard has a transverse head 34 constitutin the burner proper and provided with a perfbrated burner plate 35, the orifices of which are preferably arranged in two rows. The burner head contains a metal screen 36 which aids in the mixing of the air with the gas and prevents former as indicated at- 37. These small burners and mixers are very efi'ective to give a clear blue flame.

The side liners 4 inclosing the fire pit or fuel space are preferably cast iron plates and as shown in Fig. 2 they are arranged with a space between them and the inner sides of the steel fire box. It is in this space that the burners are placed and it is here that the combustion of the gas takes place. The flame spreads itself out thin and in close contact with the curved or bowed sides of the fire box. The tops of the liners are propped in by lugs 4 thereon so as to leave about a half inch space between them and the sides of the fire box; while the bottoms of the liners are curved inwardly to enlarge the spaces between them and the sides of the fire box and are .set upon the sides of the grate; the latter being spaced sufficiently from the top flanges of the ash pan to accommodate the burner standards and admit air to the burners from the ash space 7.

It is noted that the air for combustion both of the gas and of coal when used for fuel is controlled by the lever 20 of the thermostatic regulator. When used for burning gas only, the grate may be covered with some substance, preferably asbestos sheeting, so that no draft will circulate through the tire box exceptthat which passes through and around the mixers. Besides controlling the supply of air for combustion, the lever 20 is also utilized for regulating the supply of gas, by automatic control of a valve in the gas supply pipe 25. The form of valve shown (Fig. 6) comprises a hinged gate'or leaf valve 38 on the pintle of'which is a weighted lever arm 39 for closing said valve and another lever arm 40 for holding it open, the latter abutting against an arm or projection 41 carried by the lever 20, so that as the lever 20 moves inward under influence of a rise in temperature, the lever arm 40 follows it inward, thus allowing the gas valve to move toward its seat and restrict the flow of gas, or allowing it to close or shut off the gas supply in event of a sudden rise in temperature suflicient to cause the lever 20 to shut the ash door and open the check valve. i

As shown in Fig. 5, small pilot lights 42 are provided in the front of the fire box adjacent the first burner of each row, and are kept constantly burning so as to ignite the burners promptly under all circumstances; the succeeding burners taking their ignition from the first. In this connection it is noted that the burners are provided with side slotlike openings 35 in addition to those in the burner-plate. Said pilot lights are not connected with the automatic governor. They are carried by branch ipes 43 from a common supply pipe 44 which extends into the front wall of the fire box and outside the latter is provided with. a gas-controlling lever valve 45 and air shutter or intake 46.

While I have herein represented and described my invention as embodied in the type of furnace for which it is more especially designed and adapted, it should be understood however thatin its broadest aspects my invention is not limited to this type or -receptacle having the upper edges of its sides adjacent but spaced from the bottom of said receptacle, a gas supply pipe Within the ash pan. adjacent the space between the same and the fuel receptacle, and gas burners mounted on said pipe and extending between the ash pan and the fuel receptacle into the space between the receptacle and the shell to deliver the flame in said space, the sides of the ash pan being extended to the shell to prevent access of air to the burners from the space below the ash pan.

2. In a stove or furnace, the combination of a fire box or shell, a receptacle for solid fuel within the shell having a grated bottom and having its sides spaced from the shell at both top and bottom, an ash pan below said receptacle having the upper edges of its sides adjacent but spaced from the bottom of said receptacle, a gas supply pipe Within the ash pan adjacent the space between the same and the fuel receptacle, and combined burners andair and gas mixers mounted on said pipe with the burners proper arranged to deliver the flame in the space between the receptacle and the shell, the sides of the ash pan being extended to the shell to prevent access of air to the burners from the space below the ash panv l 3. In stove or furnace, the combination of a fire box or shell, a receptacle for solid fuel secured within the shell having its sides spaced from the shell at both top and hottom, an ash pan below said receptacle having its sides bearing upon the sides of the shell and extending to points adjacent but spaced from the sides of the receptacle, a gas supply pipe Within the ash pan adjacent the space between the same and the fuel receptacle and provided with outlet openings in its upper side, and combined mixers and burners mounted on said pipe with the burners arranged to delivert-he flame in the space between the receptacle and the shell and comprising hollow standards resting on said pipe over openings therein to direct gas to the burners and provided at their lower ends with openings to receive air from within the ash pan.

I 4. In a stove or furnace, the combination of a fire box or shell, a fuel receptacle therein and spaced therefrom, an ash space below said receptacle and closed to the lower portion of the shell, a door controlling the admission of air to the ash space, gas pipes extending longitudinally in the ash space, burners on said pipes extending into the spaces between the fuel receptacle and the shell, a controlling valve for said gas pipes having an external upstanding arm, and a thermostatic lever mountedon the shell and operated thereby, said lever engaging the air-controlling door and havin a lateral arm bearing against the upstan ing arm of the gas-controlling valve.

In a stove or furnace, the combination of a fire box or shell, a fuel receptacle therein and spaced therefrom, an ash space below said receptacle and closed to the lower portion of the shell, gas pipes extending longitudinally in the ash space, burners on said pipes extending into the spaces between the fuel receptacle and the shell, a controlling valve for said gas pipes having an external upstanding arm, and a thermostatic lever mounted on the shell and operated thereby, said lever having a lateral arm bearing against the upstanding arm of the gascontrolling valve.

In testimony whereof I allix my signature in presence of two witnesses.

MILTON J. FARQLUHAR.

Witnesses:

NATHAN M. Lm'ron, FRANK BABE. 

